Research & Sources

Just 5% of in-network ACA Marketplace denials cite "lack of medical necessity" — most cite administrative, coverage, referral, or other reasons

KFF

Claims Denials and Appeals in ACA Marketplace Plans, 2024 — full breakdown: 36% "Other" (unspecified), 25% Administrative, 16% Excluded service, 9% Lack of prior authorization or referral, 5% Medical necessity, plus smaller categories.

19% of in-network ACA Marketplace claims were denied in 2024 — similar to 2023 and to previous years

KFF

Claims Denials and Appeals in ACA Marketplace Plans, 2024 — out-of-network denial rate: 37%. Denial rates ranged from 3% to 36% across insurers in HealthCare.gov states.

Approximately 85 million in-network claims were denied on HealthCare.gov in 2024 (out of ~451 million processed)

KFF

Marketplace Plan Transparency Data Analysis, 2024 — derived from the 19% in-network denial rate applied to total claim volume.

HealthCare.gov issuers separately reported 262,982 internal appeals — appeal volume equal to about 0.31% of reported in-network denials

KFF

The appeal and denial fields are aggregate reporting, not linked case records, so 0.31% is best described as an appeal-volume ratio rather than proof that a specific share of individual denials went unappealed. CMS also suppresses small values, making 262,982 a minimum. The field covers formal internal appeals, not informal phone calls or other pushback.

Insurers overturned 34% of internally appealed HealthCare.gov denials in 2024 — down from 44% in 2023. The internal-appeal success rate declined year over year

KFF

Claims Denials and Appeals in ACA Marketplace Plans, 2024 (published March 2026) — KFF analysis of CMS Transparency in Coverage filings covering roughly 496 million claims from 157 reporting insurers. Transparency note: an older "44% overturned" figure circulated widely from the 2023 data; the 2024 data replaced it, and Lysco updated every page that used it. Even at 34%, roughly one in three internal appeals succeeds — while formal appeal volume runs well under 1% of denials.

About half of insured adults who were denied care challenged the denial informally (usually by phone) — but only 15% of consumers with denied claims filed a formal appeal

The Commonwealth Fund / KFF

Commonwealth Fund 2025 Health Care Affordability Survey (released June 2026) — roughly half of denied patients pushed back in some form. Among those who challenged: 30% got the recommended care approved, 25% got an alternative covered, and 33% got a bill reduced or eliminated. KFF's 2023 Survey of Consumer Experiences with Health Insurance found only 15% filed a formal appeal. This is why Lysco scopes every appeal-gap figure to formal appeals and states it as a volume ratio — the unscoped version would be wrong.

21% of privately insured working-age adults had care denied by their insurer in the past year

The Commonwealth Fund

2025 Health Care Affordability Survey (released June 2026). Over half of the denied bills were $1,000 or more, and about 70% of those denied said the denial cost their household more money.

43% of insured adults whose claim was denied say the denial created medical debt they are still paying off

The Commonwealth Fund

2025 Health Care Affordability Survey (released June 2026).

4 in 5 appealed Medicare Advantage prior-authorization denials (80.7%) were fully or partially overturned in 2024

KFF

Medicare Advantage Insurers Made Nearly 53 Million Prior Authorization Determinations, 2024 (published January 2026) — KFF analysis of CMS contract-level reporting data covering essentially all MA contracts. Caveats: "partially overturned" counts as an overturn, the rate is measured at plan-level (first-level) appeal, and people who appeal are a self-selected group with stronger cases. By insurer, 2024 overturn rates ran from 51.0% (Kaiser Foundation Health Plan) to 95.5% (Centene).

Historical: Medicare Advantage plans overturned 75% of their own denials on appeal in 2014–2016 — roughly 216,000 denials a year

HHS Office of Inspector General (OIG), report OEI-09-16-00410

"Medicare Advantage Appeal Outcomes and Audit Findings Raise Concerns About Service and Payment Denials," issued September 25, 2018, covering 2014–2016 appeal data. Listed for historical continuity only — the current figure Lysco cites is the 80.7% KFF 2024 number above. Correction note: an earlier version of this page attributed the 75% to OIG report OEI-09-18-00260 (the 2022 prior-authorization study), which does not contain it.

82% of Medicare Advantage skilled-nursing admission denials went unappealed; among the 2,445 appeals filed, 95% (2,313) were overturned

HHS Office of Inspector General (OIG), June 2026

Report OEI-09-24-00331 analyzed June 2024 data from 19 large Medicare Advantage organizations covering 29.3 million enrollees, or 86% of Medicare Advantage enrollment at the time. The organizations denied about 13,500 of 109,400 skilled-nursing-facility admission requests; enrollees or providers appealed 2,445 denials, and plans overturned 2,313 in favor of the enrollee. Scope caveat: this was one month of one service category, and OIG said the aggregate analysis could not determine how many initial denials were inappropriate.

Only 11.5% of Medicare Advantage prior-authorization denials are appealed

KFF

Medicare Advantage prior-authorization data, 2024 reporting cycle (published January 2026). 4.1 million MA prior-auth denials in 2024 (7.7% denial rate, up from 5.7% in 2019).

HHS OIG estimated that 13.3% of denied Medicare Advantage prior-authorization requests met Medicare coverage rules

HHS Office of Inspector General (OIG), April 2022

Report OEI-09-18-00260 reviewed a stratified sample of 247 eligible prior-authorization denials representing 12,273 denials issued by 15 large Medicare Advantage organizations during June 1–7, 2019. OIG projected that 1,631 of those denials met Medicare coverage rules (13.3%; 95% confidence interval: 8.9%–19.3%) and likely would have been approved under original Medicare. The organizations represented nearly 80% of Medicare Advantage enrollment; this one-week 2019 sample should not be presented as a current rate for every plan or service.

Published external-review outcomes vary widely by state and case type

CA DMHC, MD Insurance Admin, CT OHA, PA Insurance Dept, NY DFS

The cited programs range from 42% fully plus 2% partially overturned in New York (2023) to about 80% reported by Connecticut's Office of the Healthcare Advocate. California IMR reports ~73%, Maryland 64%, and Pennsylvania ~50%. These figures are not a prediction for an individual case.

Only 40% of US consumers know they have a legal right to appeal externally

KFF

Survey of Consumer Experiences with Health Insurance, 2023 — 51% are unsure; 9% don't believe they have appeal rights. Marketplace enrollees are least aware (34%).

66% of insured adults call insurance delays and denials a "major problem" — and 33% had a service or medication denied in the past two years

KFF

KFF health tracking polling, January 2026. Spans employer, Marketplace, Medicare, and Medicaid coverage.

States have begun outlawing AI as the sole basis for a claim denial — Arizona, Maryland, Nebraska, and Texas have enacted limits

State insurance statutes, 2024–2026

Enacted in response to insurer claim-automation revelations, including reporting that one major insurer's review system denied 300,000+ claims at an average of 1.2 seconds of physician review each — now the subject of active litigation.

95% of surveyed physicians report that prior authorization delays access to necessary care, and 26% report it led to a serious adverse event for a patient in their care

American Medical Association (AMA)

2025 AMA Prior Authorization Physician Survey — a 44-question web survey administered December 2025 to 1,000 practising US physicians (400 primary care / 600 specialists) drawn from the Medscape panel, published 2026. Also: 94% report PA increases physician burnout; 79% report PA can at least sometimes lead to treatment abandonment; 35% report PA criteria are rarely or never evidence-based; 40% report PAs are often or always denied. Scope caveat: these are physician survey responses about their own practice experience, not measured patient incidence rates.

Physicians and their staff spend about 13 hours a week completing prior authorizations

American Medical Association (AMA)

2025 AMA Prior Authorization Physician Survey (same instrument as the entry above). 40% of physicians have staff who work exclusively on prior authorizations.

US hospitals spend an estimated $19.7 billion per year managing denied claims

Premier Inc.

Premier Trend Alert, "Private Payers Retain Profits by Refusing or Delaying Legitimate Medical Claims," published March 21, 2024. National survey of hospitals, health systems, and post-acute providers: nearly 15% of claims to private payers are initially denied; providers spend an average of $43.84 per claim fighting them; 54.3% of denied private-payer claims are ultimately overturned and paid.

Cigna doctors denied over 300,000 requests for payment using an algorithmic review process, averaging 1.2 seconds per case

ProPublica (March 2023, Marshall Allen)

Investigation into Cigna's PXDX system. Findings were repeated verbatim in California and Connecticut federal class-action complaints filed in 2023.

UnitedHealthcare's skilled-nursing-facility denial rate increased ninefold (9x) from 2019 to 2022, coinciding with the deployment of an internal AI tool (nH Predict)

US Senate Permanent Subcommittee on Investigations

Refusal of Recovery: How Medicare Advantage Insurers Have Denied Patients Access to Post-Acute Care, October 2024. Report focused on UnitedHealth's NaviHealth subsidiary.

Medicare Advantage processed 53 million prior-authorization determinations in 2024

KFF

Nearly 53 million (52.8 million) determinations, up from 49.8 million in 2023. 4.1 million denials at a 7.7% denial rate. Prior-auth denial rate by parent company: UnitedHealth Group 12.8%; Centene 12.3%; CVS Health (Aetna) 11.9%; Kaiser Foundation Health Plan 10.9%; Humana 5.8%; Elevance Health 4.2%. Insurers with fewer than 1 million MA enrollees are grouped as "other insurers" (5.5%).

CMS 2026 rule: 72-hour urgent / 7-calendar-day standard prior-authorization decisions required for Medicare Advantage, Medicaid, and CHIP plans

Centers for Medicare & Medicaid Services (CMS)

CMS Interoperability and Prior Authorization Final Rule (CMS-0057-F). "Impacted payers" are Medicare Advantage organizations, state Medicaid and CHIP fee-for-service programs, Medicaid and CHIP managed care plans, and qualified health plan issuers on the federally facilitated exchanges (FFEs). The decision timeframes apply to MA, Medicaid, and CHIP plans; FFE Marketplace QHPs are excluded from the timeframes (their urgent decisions follow ACA claims rules, 45 CFR 147.136) but must give specific denial reasons and post metrics. Plans sold on fully state-run exchanges may fall outside the rule. Commercial and ERISA self-funded plans are not impacted payers. Drug prior authorization is outside the rule; the drug PA rule (CMS-0062-P) is proposed, with compliance proposed for Oct 2027.

A typical flat-fee consumer appeal-letter service charges about $40 per appeal ($39.95 plus shipping)

Claimable — published pricing

Claimable's published flat fee of $39.95 + shipping per appeal, fetched from its public pricing page July 3, 2026. This is the basis for the "~$40 per appeal" comparison on our pricing page; Lysco does not evaluate or endorse the service itself.

Americans owe an estimated $220 billion in medical debt

KFF analysis of the Survey of Income and Program Participation (SIPP)

"The Burden of Medical Debt in the United States," published February 12, 2024, using data from the 2021 SIPP. Debt distribution is highly skewed: ~14 million Americans (6% of adults) owe more than $1,000; ~3 million (1%) owe more than $10,000. This is a "$220 billion at least" floor, not a ceiling.

100 million Americans carry medical or dental debt

KFF/NPR

Health Care Debt Survey, 2022 — broader definition (includes past-due bills, balances being paid off over time, medical credit cards, and personal loans for healthcare). Roughly 41% of US adults.

36% of US households carried medical debt in 2024 — roughly $194 billion estimated in active collections

JAMA (analysis of two nationally representative 2024 surveys)

21% of households had a past-due medical bill and 23% were paying one off over time. Complements KFF's broader $220B total-owed estimate and CFPB's narrower credit-report figure — each measures a different slice of the same problem.

About two-thirds of US consumer bankruptcies (~66.5%) cite medical bills as a contributor

Himmelstein et al., American Journal of Public Health

Medical Bankruptcy: Still Common Despite the Affordable Care Act, 2019 — 65.5% pre-ACA / 67.5% post-ACA. Broad-definition study (any household with >$1,000 in medical bills, mortgaging a home for medical bills, or losing 2+ weeks of work to illness). More conservative definitions place medical-cause bankruptcies in the 20–60% range.

31 million Americans borrowed an estimated $74 billion in 2024 to pay for healthcare

West Health-Gallup Healthcare Survey

Fielded November 11–18, 2024 (n=3,583); published March 5, 2025. 11% of US adults are classified as "Cost Desperate" — unable to afford or access quality care.

63% of US adults could not cover an unexpected $400 expense entirely with cash or equivalent

Federal Reserve — Survey of Household Economics and Decisionmaking (SHED), 2024

Roughly 30% could not cover three months of expenses by any means. 26% of US adults skipped some form of medical treatment in 2025 because they could not afford it.

Approximately 50% of US adults could not pay an unexpected $500 medical bill without borrowing

KFF

Health Care Debt Survey and follow-up reporting. Of those, 19% could not pay it at all; 5% would have to borrow from a bank, payday lender, or family; 21% would put it on a credit card and carry the balance.

As of June 2023, an estimated 15.6 million consumers had at least $49.2 billion in medical collections on their credit records

Consumer Financial Protection Bureau (CFPB), March 2024

CFPB found 325,788 consumers with a medical collection in its roughly 1-in-48 Consumer Credit Panel and scaled that count to an estimated 15.6 million consumers. It similarly estimated $49.2 billion in medical-collection balances at the nationwide credit-reporting agency supplying the panel. CFPB describes $49.2 billion as a lower bound: collections are not always reported to every bureau, many are never credit-reported, and total medical debt is larger than medical debt in collections.

Roughly 1 in 5 US hospitals have denied non-emergency care to patients with unpaid bills

KFF Health News — "Diagnosis: Debt"

Investigative series, 2022–2024. Many additional hospitals retain formal policies allowing the practice even when not actively enforced. Some hospitals also push patients toward medical credit cards charging up to 29% interest.

Around 250,000 medical fundraising campaigns are launched on GoFundMe per year

GoFundMe / NORC at the University of Chicago

GoFundMe's then-CEO Rob Solomon told CBS MoneyWatch in January 2019 that "one-third of all donations on GoFundMe goes towards health care costs." A peer-reviewed study of 437,596 medical campaigns (2016–2020) found only 12% met their funding goal in 2020.

61.8% of people who negotiated a problematic medical bill reported a lower price

JAMA Health Forum

Disparate Patient Advocacy When Facing Unaffordable and Problematic Medical Bills, 2024.

Nonprofit hospitals are required to maintain financial assistance policies (501(r))

Internal Revenue Service (IRS)

Section 501(r) Requirements for Charitable Hospitals — requires policies to be widely publicized and limits how much can be charged to patients eligible for assistance.

About 1 in 5 US adults recently got a medical bill they disagreed with or could not afford — and of those who contacted the biller about a perceived error, 74% got the mistake corrected

JAMA Health Forum / USC Schaeffer Center

Peer-reviewed study published August 2024, using the probability-based, nationally representative Understanding America Study panel (n=1,135; fielded August–October 2023). 62% of those who negotiated a price got it lowered. Caveats: outcomes are self-reported, and the success rates are measured among the roughly 6 in 10 billed adults who chose to reach out — not among everyone with a problem bill.

Medicare paid an estimated $28.8 billion improperly in fiscal year 2025 — 6.55% of Medicare Fee-for-Service dollars

CMS Comprehensive Error Rate Testing (CERT) program

FY2025 Improper Payments Fact Sheet (FY2024: 7.66%, $31.7 billion). A federal audit that re-reviews statistically sampled claims against medical records. Caveats: "improper" includes insufficient documentation and underpayments, not only overcharges, and the rate is dollar-weighted for Medicare Fee-for-Service only — it cannot be read as "X% of bills contain errors."

Retired claims: "49–80% of medical bills contain errors" and "$1,300 average error on hospital bills over $10,000"

Historical — NerdWallet Health (2014) / Medical Billing Advocates of America

These widely repeated figures trace to a 2014 NerdWallet analysis of OIG Medicare hospital-compliance audits and to unpublished reviews by a billing-advocacy group; a 1990s Equifax audit of large hospital bills sits behind many "$1,300" citations. No study published since 2020 supports a per-bill error rate or average error dollar figure of that shape, so Lysco retired both claims in July 2026 and no longer cites them. They are listed here for transparency because older articles still repeat them. The strongest modern evidence that challenging bills works is the 2024 JAMA Health Forum study above.

Average emergency-department visit total cost: $2,453; out-of-pocket for large-employer coverage averages $646

Peterson-KFF Health System Tracker

Cost analysis of ED visits, 2024. Appendicitis ED visits run ~$9,535 total ($1,717 out-of-pocket). Uninsured patients pay roughly $2,600 on average per visit.

HIPAA access rights may include billing records held by covered entities

US Department of Health and Human Services (HHS)

45 CFR §164.524 generally lets an individual inspect or obtain a copy of protected health information in a designated record set held by a HIPAA-covered entity, including billing records. It does not guarantee a custom itemized bill from every provider. State law may add itemized-statement rights, and HIPAA timing and extension rules apply to covered access requests.

Contingency medical-bill negotiators and billing advocates keep 10–35% of whatever they save you

Consumer Reports / published service pricing

Consumer Reports: billing advocates working on contingency usually take 25–35% of savings (CoPatient charged 35%). Published service rates as of 2026: Goodbill charges 20% of savings capped at $1,000; Resolve charges a tiered 10–25% of savings plus an upfront deposit. Hourly advocates run ~$75–$150/hr.

No Surprises Act IDR volume more than doubled year over year — 1.2 million new disputes in the first half of 2025 against nearly 590,000 in the first half of 2024

Georgetown Center on Health Insurance Reforms (CHIR), analysis of CMS IDR public use files

Cumulative volume reached 3.4 million disputes from 2022 through June 2025, and nearly 1.4 million more were filed July–December 2025, for 4.8 million total through the end of 2025. Federal officials had expected roughly 17,000 disputes a year. Providers won 88% of determinations in the first half of 2025, up from 85% in 2024 and 81% in 2023. CHIR estimated total IDR-related costs at about $5 billion through the end of 2024, and expects that figure to have risen substantially through 2025.

A final bill that is $400+ over the Good Faith Estimate triggers Patient-Provider Dispute Resolution

Centers for Medicare & Medicaid Services (CMS)

No Surprises Act — Patient-Provider Dispute Resolution process. Available to self-pay and uninsured patients.

45% of insured working-age adults received a medical bill or copay charge in the past year for care they believed should have been free or covered

The Commonwealth Fund

Unforeseen Health Care Bills and Coverage Denials by Health Insurers in the U.S., August 2024 — nationally representative survey (n=7,873 adults; 5,602 insured working-age adults analyzed; fielded April–July 2023). 17% said their insurer denied coverage for doctor-recommended care. Caveat: this is self-reported perception — some of these bills reflect a misunderstanding of benefits rather than a verified billing or coverage error.

36% of US adults skipped or postponed care due to cost in the past 12 months

KFF Tracking Poll

2024 tracking poll. 75% of uninsured adults went without needed care. 37% of insured adults still skipped care due to cost. 18% of all adults said their health got worse because of skipped or delayed care.

43% of US adults did not take medication as prescribed because of cost

KFF

Including 27% who did not fill a prescription, 19% who cut pills in half, and others who skipped doses or substituted over-the-counter drugs.

Roughly 30% of people with a chronic illness skip doses, cut pills in half, or leave prescriptions unfilled due to cost

KFF

Includes about 25% of adults who had health insurance for the full year.

National health spending reached $5.3 trillion in 2024 (18.0% of GDP) — about $15,474 per person

Centers for Medicare & Medicaid Services (CMS)

National Health Expenditure Accounts, 2024. Hospital spending: $1.63T (+8.9%); physician services: $1.11T (+8.1%); prescription drugs: $467B (+7.9%).

US per-capita health spending is roughly 2x the wealthy-country OECD average

OECD / Peterson-KFF

~$14,885/person in 2024 vs. ~$7,371 OECD wealthy-country average. Switzerland is the next-highest at $9,963. The US spends >$1,000 per person on administrative costs alone, roughly 5x the OECD wealthy-country average.

Health spending is projected to reach 20.3% of GDP by 2033

CMS Office of the Actuary

National Health Expenditure Projections 2024–2033. Average annual growth of 5.6%, outpacing GDP growth of 4.3%. Medicare spending projected to grow 7.4%/year through 2032.

Average employer-sponsored family premium: $26,993 in 2025 (+6% YoY, +24% over five years)

KFF

2025 Employer Health Benefits Survey. Single coverage: $9,325. Workers contribute $6,850 toward family coverage on average. 34% of covered workers face a deductible ≥$2,000 (53% at small firms with 10–199 workers).

44% of adults say healthcare costs are difficult to afford

KFF

Health Care Costs Survey, 2024.

23% of working-age adults with year-round coverage are underinsured

The Commonwealth Fund

Biennial Health Insurance Survey, 2024. 66% of the underinsured have employer coverage. 57% reported avoiding care due to cost; 44% had medical debt.

27.1 million Americans were uninsured in 2024 (8% of the population)

US Census Bureau

Current Population Survey and American Community Survey, 2024. Working-age (19–64) uninsured rate: 11.3%. The ACS-measured uninsured rate ticked up from 7.9% in 2023 — the first increase in years, driven mostly by Medicaid unwinding.

24.2 million Americans enrolled in ACA Marketplace coverage in 2025

CMS

More than double the 12 million enrolled in 2021, driven by enhanced premium tax credits.

Roughly 27 million people disenrolled from Medicaid after the post-pandemic unwinding

KFF / GAO

KFF Medicaid Enrollment and Unwinding Tracker. 69% of disenrollments were procedural (not eligibility-based).

If enhanced ACA premium tax credits expire, subsidized enrollees' premiums could rise 114% — from $888 to $1,904/year

KFF / CBO

KFF analysis, September 2025. CBO projects ~10 million more people uninsured by 2034 under the 2025 "One Big Beautiful Bill Act" plus subsidy expiration.

The subsidy cliff arrived: benchmark ACA premiums rose ~26% for 2026, and ~9% of 2025 enrollees were already uninsured by early 2026

KFF

Enhanced premium tax credits expired at the end of 2025. Average paid premiums rose ~58% as many enrollees bought down to higher-deductible plans; 55% of re-enrollees report cutting basic household spending to keep coverage.

Hispanic Americans face the highest uninsured rate at 24.6% among adults 18–64

KFF / National Health Interview Survey (NHIS)

2024 NHIS data — nearly four times the rate of non-Hispanic Whites (7.9%).

92.3 million people live in primary-care shortage areas

Health Resources and Services Administration (HRSA)

Health Professional Shortage Area Statistics, January 2026.

137.1 million people live in mental-health shortage areas

HRSA

Mental Health HPSA Designations.

Projected 141,160 FTE physician shortfall by 2038

HRSA

Physician Workforce Projections, 2025.

76.4% of adults had at least one chronic condition (2023)

Centers for Disease Control and Prevention (CDC)

National Health Interview Survey, Chronic Condition Surveillance. 51.4% had multiple chronic conditions.

Over-65 population projected to reach 21% of total by 2040

Economic Report of the President, 2024

Chapter on Population and Aging.

Medicaid Long-Term Services and Supports: 9.7 million users; $228.6 billion in expenditures (2023)

CMS

Medicaid LTSS Annual Expenditures Report.